Abstract 13 A Randomized, Placebo-Controlled, Phase II Trial of Intravenous Allogeneic Umbilical Cord Blood Infusion for Adults with Ischemic Stroke

Introduction

Stroke is the fifth leading cause of death in the United States. Tissue plasminogen activator and mechanical thrombectomy are the only effective treatments, but many patients are ineligible for these treatments.

Objective

The objective of this study was to determine whether an intravenous infusion of a non-HLA matched, unrelated donor umbilical cord blood (UCB) would improve functional outcomes.

Methods

We conducted a phase II multicenter, randomized (2:1), placebo controlled, double-blinded trial of UCB in adults with acute ischemic stroke. Patients had to have adequate immune function. Cord blood units were selected from U.S. public cord banks based on blood type, race, and cell dose. Study product was infused 3-10 days post stroke. Participants were randomized within strata of National Institutes of Health Stroke Scale Score (NIHSS) (<12 vs ≥12), and study center. The primary endpoint was change in Modified Rankin Scale (mRS) (baseline minus day 90). The study was powered at 80% (odds ratio of 2). Key secondary outcomes included functional independence at day 90 (mRS <2), NIHSS, the Barthel Index, infusion reactions, and adverse events.

Results

Seventy-nine participants were enrolled at 6 centers when the trial was closed early due to slow accrual related to COVID19; 73 participants (47 randomized to UCB) were included in the safety and efficacy analyses. The median (range) of the change in mRS was 1 (–2, 3) in UCB and 1 (–1, 4) in placebo. A shift analysis based on the proportional odds model showed an odds ratio of 0.9 (95% CI: 0.4, 2.3) after adjustment for baseline mRS and randomization strata. No differences were observed on the key secondary outcomes. There were 17 mild infusion reactions (27.6% UCB; 15.4% placebo). The distribution of serious and non-serious adverse events was similar between arms.

Discussion

This study demonstrated the safety of infusing non-HLA matched UCB to adults with acute ischemic stroke. Feasibility and logistics were challenging. The primary efficacy endpoint did not demonstrate benefit in this underpowered sample size. In a secondary ad hoc analysis, a trend of improved functional outcomes at day 90 in recipients of UCB more than 5 days post stroke (Figure 1) could be explored in future trials.

Abstract WP234: Improved Response, Neurologic Evaluation, and Treatment Timing With a Mobile Stroke Unit in a Large Urban Population

Background: The University of Colorado Mobile Stroke Unit (UC MSU) began clinical operation in January 2016, providing ambulance-mounted CT scanning and tele-stroke neurologic assessment in the Denver, CO, metropolitan area. As one of the first U.S. tertiary stroke centers to utilize a mobile stroke protocol we sought to evaluate characteristics of response, neurologic evaluation, and treatment of the MSU.

Methods: The study assessed patient, stroke, ambulance response, neurologic evaluation, and treatment characteristics of the UC MSU for its initial year in service. Variables included time from stroke alert (MSU dispatch) to brain CT in the field, treatment decision, tPA administration, and transport to a hospital stroke center. Time intervals from last seen normal were calculated for all patients. Study variables were compared for patients treated with thrombolysis on the MSU, and those who were not; and with reported times for other MSUs, and hospitals.

Results: Between Jan. 15, 2016 and Jan. 9, 2017, 47 individuals received prehospital management with the UC MSU. Median age was 67 years (IQR 58-77), and 51% were female. Median initial NIH Stroke Scale score was 5 (IQR 2-11), and 36% were moderate to severe (NIHSS ≥8). Thirteen (28%) of patients were treated with IV tPA on the MSU. Median times from stroke alert to MSU arrival on the scene and first CT were 7 minutes (IQR 5-8), and 20 minutes (IQR 18-24), respectively. Median time to tPA administration was 39 minutes (IQR 35-45) from stroke alert, and 52 minutes (IQR 48-77) from the last time the patient was seen normal. Times from stroke alert and last seen normal to arrival at a stroke hospital were a median of 51 minutes (IQR 45-54) and 71 minutes (IQR 56-118), respectively.

Conclusions: In this study of the initial year of an urban MSU’s operation, time intervals from stroke alert to initial brain CT imaging, neurologic evaluation and administration of thrombolysis were found to be substantially reduced compared to conventional, hospital-based stroke protocols, and some earlier MSUs. Intervals from last seen normal to these procedure time points were similarly reduced. These results suggest prehospital management with an MSU has potential to aid the goal of earlier thrombolysis after ischemic stroke symptom onset.

Abstract TMP72: Technological Innovation in a Mobile Stroke Treatment Unit

Background: University of Colorado Hospital, under the UCHealth system, developed a Mobile Stroke Unit (UCHealth MSU) which began clinical operation in January 2016 and added a second operational location in August 2016. As one of the first centers to institute ambulance-mounted brain imaging and neurologic evaluation and treatment in the field for acute stroke in the U.S., it was necessary to design unique, dynamic IT systems for operationalizing the MSU. These include high speed cellular, HIPAA-compliant cloud based environments and remote access to patient electronic medical records (EMR) and a reliable means for rapid image transfer. Here we describe novel technologies engineered and incorporated into the UCHealth MSU.

Methods: Technological data-handling aspects of the UCHealth MSU were reviewed. Functions evaluated included wireless connectivity while in transit, EMR capability in the field, computed tomography (CT) scanning and image transfer, and communications for tele-stroke neurologic assessment.

Results: The UCHealth MSU began clinical operation in January 2016, Wireless communications were designed with redundancy to avoid dropped signals during data transfer. Two IP destinations were assigned for videoconferencing and EMR data transfer, with split-tunnel architecture to direct traffic to each. Placement of the MSU antenna inside the unit reduced interference from home and business Wi-Fi routers encountered. Brain imaging acquired in the ambulance CT scanner is transferred initially to an onboard laptop, then via Citrix Receiver to a hospital-based server and can be visualized by the stroke neurologist, neuroradiologist and all other care providers. Picture Archiving Communications System (PACS) and Radiology Information System (RIS) are two of the XenApps used by CT technologists.

Conclusions: Technological hurdles associated with remote imaging, assessment, and treatment, are critical to overcome if time-saving benefits of mobile stroke protocols are to be recognized. Innovative and unique techniques developed to accommodate wireless communication and image transfer from the field in the UCHealth MSU may aid start-up of similar units elsewhere and serve as a framework to further improve this technology.

Reduced Na(+), K(+)-ATPase activity in erythrocyte membranes from patients with phenylketonuria

Na(+), K(+)-ATPase activity was determined in erythrocyte membranes from 12 phenylketonuric patients of both sexes, aged 8.8 +/- 5.0 y, with plasma phenylalanine levels of 0.64 +/- 0.31 mM. The in vitro effects of phenylalanine and alanine on the enzyme activity in erythrocyte membranes from healthy individuals were also investigated. We observed that Na(+), K(+)-ATPase activity was decreased by 31% in erythrocytes from phenylketonuric patients compared with normal age-matched individuals (p < 0.01). We also observed a significant negative correlation between erythrocyte Na(+), K(+)-ATPase activity and plasma phenylalanine levels (r = -0.65; p < 0.05). All PKU patients with plasma phenylalanine levels higher than 0.3 mM had erythrocyte Na(+), K(+)-ATPase activity below the normal range. Phenylalanine inhibited in vitro erythrocyte Na(+), K(+)-ATPase activity by 22 to 34%, whereas alanine had no effect on this activity. However, when combined with phenylalanine, alanine prevented Na(+) K(+)-ATPase inhibition. Considering that reduction of Na(+), K(+)-ATPase activity occurs in various neurodegenerative disorders leading to neuronal loss, our previous observations showing a significant reduction of Na(+), K(+)-ATPase activity in brain cortex of rats subjected to experimental phenylketonuria and the present results, it is proposed that determination of Na(+), K(+)-ATPase activity in erythrocytes may be a useful peripheral marker for the neurotoxic effect of phenylalanine in phenylketonuria.

Platelet Na+, K+-ATPase activity as a possible peripheral marker for the neurotoxic effects of phenylalanine in phenylketonuria

The in vitro effects of phenylalanine or alanine alone or combined on Na+, K+-ATPase activity in membranes from human platelets were investigated. The enzyme activity was assayed in membranes prepared from platelet-rich plasma of healthy donors. Phenylalanine or alanine were added to the assay to final concentrations of 0.3 to 1.2 mM, similar to those found in plasma of phenylketonuric patients. Phenylalanine inhibited Na+, K+-ATPase activity by 20-50% [F(4,25)=11.47 ; p<0.001]. Alanine had no effect on Na+, K+-ATPase activity but when combined with phenylalanine prevented the enzyme inhibition. These results, allied to others previously reported on brain Na+, K+-ATPase activity, may reflect a general inhibitory effect of phenylalanine on this important enzyme activity. Therefore, it is possible that measurement of Na+, K+-ATPase activity in platelets from PKU patients may be a useful peripheral marker for the neurotoxic effects of phenylalanine.